When Mother Nature Does the Pruning

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All those branches lying on the ground fell during a winter storm … but the trees were actually little damaged. A quick spring cleanup and possibly a bit of pruning will be enough to put things right. Source: www.ontarioparks.com

Mother Nature doesn’t put up with weakness. She ruthlessly roots out unfit animals and plants. In the winter, she sends showers of snow and freezing rain that accumulate on branches and snap them off and even pull down entire trees. In other seasons, it can be heavy rains and howling winds that do the damage, leaving the ground littered with branches. Then suddenly, the storm is over and we humans are left with a messy cleanup job to undertake.

We tend to see this kind of damage as a disaster, but it isn’t. Not from Ma Nature’s point of view. The branches ripped off were generally dead, dying or weak. When an entire tree goes, it’s usually because it was weak or old or in the wrong place. For example, a sun-loving pioneer species no longer able to cope with shade as a forest fills in. If we let nature takes its course, weak specimens will simply be replaced by strong ones.

Not that people like to let nature take its course. We instead like to interfere: trying to knock ice off branches with a hammer, staking and propping up weak branches, replacing a failed tree with exactly the same species, etc.

Learning to Live With Ma Nature’s Pruning

When a tree or shrub suffers storm damage, it’s worthwhile talking a bit of time considering what to do. And if the damage happens during the winter, you may have months to think about things: you won’t have to react until spring.

Shrub Rejuvenation

In the case of most shrubs, for example, serious damage can indicate it’s time to do a bit of rejuvenation pruning: cutting it back  to 6 to 12 inches (15 to 30 cm) above the ground, so new, healthier growth can sprout from the base. This will renew the whole shrub, which can even look better than ever in a year or two.

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The broken branches on this aging lilac suggest it’s time to prune it down and let it rejuvenate. Source: Bobscaping

For example, an old lilac may be snapped off by an ice or wind storm … yet if you look at what’s left of the trunk, it was full of holes pierced by lilac borers, as sign the end was near. Cut out what’s left of the trunk and any other old branches and soon newer, healthier growth will replace it.

Conifer Damage

On conifers, broken branches can often be traced back to overfertilizing: too much nitrogen fertilizer tends to stimulate fast but weak growth. Established conifers don’t really need fertilizing. Just let them be.

You can’t do rejuvenation pruning on most evergreens: they won’t resprout from old wood (yews being a rare exception). The best you can do is to prune back to healthy but green growth and see what happens.

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Conifers bent under the weight of snow can startle their owner,  but most recover fully Source: missouribotanicalgarden

When a conifer bends to the ground under the weight of snow or ice, it will probably straighten back up again when warmer weather comes in. You can brush the snow off if it’s light, but leave ice or clinging snow alone: you can damage the plant trying to remove it. Just remember that the snow or ice will melt away eventually.

When spring comes and the conifer doesn’t quite regain its form, don’t hesitate to stake it temporarily to help it, but … consider pruning it in the future to slow down its growth and let its wood lignify, since bending is usually linked to rapid, weak growth.

If the damage was to a conifer hedge—which, in passing, is not a normal way for evergreens to grow—, do your best to prune it back into shape while remaining “within the green” when you do so. In the future, you’ll need to prune regularly to keep growth dense and compact so that branches do what you want, because Mother Nature’s pruning scheme won’t always match your own.

Trees May Profit From Storms

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Much of what breaks off trees during a storm is actually dead or dying branches. Source: Tom Shortell, Wikimedia Commons

In general, storm damage to trees is fairly innocuous … from the tree’s point of view. Plenty of dead or weak branches may litter the ground that you’ll want to pick up (at least in a garden setting; in a natural woodland, you can just leave them alone), but usually the trees themselves are still in pretty good shape. In fact, trees do best where storms are a common occurrence and weak growth is therefore eliminated promptly. It’s when there have been years of mild weather and a truly harsh storm comes through that more serious damage tends to occur.

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If a branch is imprisoned in snow or ice, brush the snow off if you can do so gently, but don’t try to break off ice or dig out branches or straighten up a frozen branch: that will only cause worse damage. Let it melt free, even if that means waiting until spring. Source: jardinierparesseux.com

If a major limb snaps off and you judge the tree still salvageable, you’ll need to study the situation and react accordingly. Seriously consider calling in a certified arborist, not only for their opinion, but also to do the job. This is the kind of pruning that may be best done by a professional, especially if you’ll need to climb a ladder to carry it out. My firm belief is that home gardeners should always keep two feet solidly on the ground! If you decide to do it on your own, at least wear a hard hat!

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Cut any stub back to just beyond the branch collar so it will compartmentalize well. Source: jardinierparesseux.com

If the branch snapped off at the trunk, cut away any ragged bark edges, loose bark and shards of wood with a sharp knife, leaving as small a wound as possible so it can compartmentalize (cover over with bark) quickly. Don’t apply tree paint or paste. If there is still a considerable stub, cut it back to just beyond the branch collar (swelling where the branch meets the trunk). If only part of a branch is ripped off, prune back to a replacement branch pointing in the same direction as the one that broke off.

And if a tree is down entirely or is beyond repair, just accept that its time had come. Not all trees live to be centenarians, after all. Call in the arborist to remove it.

Storm damage can seem intimidating when you first see it, but think of it as a blessing in disguise: free pruning from Mother Nature!20171210D Tom Shortell, WC


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